Toyota Motor Sales U.S.A. is recalling approximately 472,500 Yaris and Scion vehicles so that dealers can make repairs to ensure front seats stay locked in position in the event of a collision.

The recall affects approximately 158,000 2006-2010 model-year Yaris Hatchbacks, 250,500 2007-2010-MY Yaris Sedans, and 64,000 2008-2010-MY Scion xDs.

In these vehicles, springs used for the mechanism that locks the seat rail in its adjusting positions are at risk of breaking. These springs are found in the seat rail of the driver seat and also the front passenger seat of three-door models. With a broken seat rail spring, the seat could move in the event of a crash. This poses a safety risk.

The problem is more likely to occur in vehicles where the seats are adjusted forward or backward on a regular basis, Toyota said. If a seat rail spring breaks, the seat may no longer lock into the adjusted position. 

Toyota said it is not aware of any accidents or injuries caused by this condition.

The automaker is currently preparing a remedy for the defect. This will involve replacing the seat track assembly. There will be no charge for this service.

Vehicle owners can reach Toyota at 1-800-331-4331.